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7#include <linux/kernel.h>
8#include <linux/uuid.h>
9#include <linux/fs.h>
10#include "ovl_entry.h"
11
12#undef pr_fmt
13#define pr_fmt(fmt) "overlayfs: " fmt
14
15enum ovl_path_type {
16 __OVL_PATH_UPPER = (1 << 0),
17 __OVL_PATH_MERGE = (1 << 1),
18 __OVL_PATH_ORIGIN = (1 << 2),
19};
20
21#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
22#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
23#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
24
25#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
26#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
27#define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
28#define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
29#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
30#define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"
31#define OVL_XATTR_UPPER OVL_XATTR_PREFIX "upper"
32#define OVL_XATTR_METACOPY OVL_XATTR_PREFIX "metacopy"
33
34enum ovl_inode_flag {
35
36 OVL_IMPURE,
37
38 OVL_WHITEOUTS,
39 OVL_INDEX,
40 OVL_UPPERDATA,
41
42 OVL_CONST_INO,
43};
44
45enum ovl_entry_flag {
46 OVL_E_UPPER_ALIAS,
47 OVL_E_OPAQUE,
48 OVL_E_CONNECTED,
49};
50
51enum {
52 OVL_XINO_OFF,
53 OVL_XINO_AUTO,
54 OVL_XINO_ON,
55};
56
57
58
59
60
61
62
63#define OVL_FH_VERSION 0
64#define OVL_FH_MAGIC 0xfb
65
66
67#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
68#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
69
70#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
71
72#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
73 OVL_FH_FLAG_PATH_UPPER)
74
75#if defined(__LITTLE_ENDIAN)
76#define OVL_FH_FLAG_CPU_ENDIAN 0
77#elif defined(__BIG_ENDIAN)
78#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
79#else
80#error Endianness not defined
81#endif
82
83
84#define OVL_FILEID_V0 0xfb
85
86#define OVL_FILEID_V1 0xf8
87
88
89struct ovl_fb {
90 u8 version;
91 u8 magic;
92 u8 len;
93 u8 flags;
94 u8 type;
95 uuid_t uuid;
96 u32 fid[];
97} __packed;
98
99
100struct ovl_fh {
101 u8 padding[3];
102 union {
103 struct ovl_fb fb;
104 u8 buf[0];
105 };
106} __packed;
107
108#define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb)
109#define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len)
110#define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \
111 offsetof(struct ovl_fb, fid))
112
113static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
114{
115 int err = vfs_rmdir(dir, dentry);
116
117 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
118 return err;
119}
120
121static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
122{
123 int err = vfs_unlink(dir, dentry, NULL);
124
125 pr_debug("unlink(%pd2) = %i\n", dentry, err);
126 return err;
127}
128
129static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
130 struct dentry *new_dentry)
131{
132 int err = vfs_link(old_dentry, dir, new_dentry, NULL);
133
134 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err);
135 return err;
136}
137
138static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
139 umode_t mode)
140{
141 int err = vfs_create(dir, dentry, mode, true);
142
143 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
144 return err;
145}
146
147static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
148 umode_t mode)
149{
150 int err = vfs_mkdir(dir, dentry, mode);
151 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
152 return err;
153}
154
155static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
156 umode_t mode, dev_t dev)
157{
158 int err = vfs_mknod(dir, dentry, mode, dev);
159
160 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
161 return err;
162}
163
164static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
165 const char *oldname)
166{
167 int err = vfs_symlink(dir, dentry, oldname);
168
169 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
170 return err;
171}
172
173static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
174 const void *value, size_t size, int flags)
175{
176 int err = vfs_setxattr(dentry, name, value, size, flags);
177 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, 0x%x) = %i\n",
178 dentry, name, min((int)size, 48), value, size, flags, err);
179 return err;
180}
181
182static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
183{
184 int err = vfs_removexattr(dentry, name);
185 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
186 return err;
187}
188
189static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
190 struct inode *newdir, struct dentry *newdentry,
191 unsigned int flags)
192{
193 int err;
194
195 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags);
196 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
197 if (err) {
198 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
199 olddentry, newdentry, err);
200 }
201 return err;
202}
203
204static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
205{
206 int err = vfs_whiteout(dir, dentry);
207 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
208 return err;
209}
210
211static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
212{
213 struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
214 int err = PTR_ERR_OR_ZERO(ret);
215
216 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
217 return ret;
218}
219
220static inline bool ovl_open_flags_need_copy_up(int flags)
221{
222 if (!flags)
223 return false;
224
225 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
226}
227
228
229int ovl_want_write(struct dentry *dentry);
230void ovl_drop_write(struct dentry *dentry);
231struct dentry *ovl_workdir(struct dentry *dentry);
232const struct cred *ovl_override_creds(struct super_block *sb);
233int ovl_can_decode_fh(struct super_block *sb);
234struct dentry *ovl_indexdir(struct super_block *sb);
235bool ovl_index_all(struct super_block *sb);
236bool ovl_verify_lower(struct super_block *sb);
237struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
238bool ovl_dentry_remote(struct dentry *dentry);
239void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry,
240 unsigned int mask);
241bool ovl_dentry_weird(struct dentry *dentry);
242enum ovl_path_type ovl_path_type(struct dentry *dentry);
243void ovl_path_upper(struct dentry *dentry, struct path *path);
244void ovl_path_lower(struct dentry *dentry, struct path *path);
245void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
246enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
247struct dentry *ovl_dentry_upper(struct dentry *dentry);
248struct dentry *ovl_dentry_lower(struct dentry *dentry);
249struct dentry *ovl_dentry_lowerdata(struct dentry *dentry);
250const struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
251struct dentry *ovl_dentry_real(struct dentry *dentry);
252struct dentry *ovl_i_dentry_upper(struct inode *inode);
253struct inode *ovl_inode_upper(struct inode *inode);
254struct inode *ovl_inode_lower(struct inode *inode);
255struct inode *ovl_inode_lowerdata(struct inode *inode);
256struct inode *ovl_inode_real(struct inode *inode);
257struct inode *ovl_inode_realdata(struct inode *inode);
258struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
259void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
260void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
261void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
262bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
263bool ovl_dentry_is_opaque(struct dentry *dentry);
264bool ovl_dentry_is_whiteout(struct dentry *dentry);
265void ovl_dentry_set_opaque(struct dentry *dentry);
266bool ovl_dentry_has_upper_alias(struct dentry *dentry);
267void ovl_dentry_set_upper_alias(struct dentry *dentry);
268bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
269bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags);
270bool ovl_has_upperdata(struct inode *inode);
271void ovl_set_upperdata(struct inode *inode);
272bool ovl_redirect_dir(struct super_block *sb);
273const char *ovl_dentry_get_redirect(struct dentry *dentry);
274void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
275void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
276void ovl_dir_modified(struct dentry *dentry, bool impurity);
277u64 ovl_dentry_version_get(struct dentry *dentry);
278bool ovl_is_whiteout(struct dentry *dentry);
279struct file *ovl_path_open(struct path *path, int flags);
280int ovl_copy_up_start(struct dentry *dentry, int flags);
281void ovl_copy_up_end(struct dentry *dentry);
282bool ovl_already_copied_up(struct dentry *dentry, int flags);
283bool ovl_check_origin_xattr(struct dentry *dentry);
284bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
285int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
286 const char *name, const void *value, size_t size,
287 int xerr);
288int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
289void ovl_set_flag(unsigned long flag, struct inode *inode);
290void ovl_clear_flag(unsigned long flag, struct inode *inode);
291bool ovl_test_flag(unsigned long flag, struct inode *inode);
292bool ovl_inuse_trylock(struct dentry *dentry);
293void ovl_inuse_unlock(struct dentry *dentry);
294bool ovl_is_inuse(struct dentry *dentry);
295bool ovl_need_index(struct dentry *dentry);
296int ovl_nlink_start(struct dentry *dentry);
297void ovl_nlink_end(struct dentry *dentry);
298int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
299int ovl_check_metacopy_xattr(struct dentry *dentry);
300bool ovl_is_metacopy_dentry(struct dentry *dentry);
301char *ovl_get_redirect_xattr(struct dentry *dentry, int padding);
302ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value,
303 size_t padding);
304
305static inline bool ovl_is_impuredir(struct dentry *dentry)
306{
307 return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
308}
309
310
311
312
313
314
315static inline bool ovl_xino_warn(struct super_block *sb)
316{
317 return OVL_FS(sb)->config.xino == OVL_XINO_ON;
318}
319
320
321static inline bool ovl_same_fs(struct super_block *sb)
322{
323 return OVL_FS(sb)->xino_mode == 0;
324}
325
326
327static inline bool ovl_same_dev(struct super_block *sb)
328{
329 return OVL_FS(sb)->xino_mode >= 0;
330}
331
332static inline unsigned int ovl_xino_bits(struct super_block *sb)
333{
334 return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0;
335}
336
337static inline void ovl_inode_lock(struct inode *inode)
338{
339 mutex_lock(&OVL_I(inode)->lock);
340}
341
342static inline int ovl_inode_lock_interruptible(struct inode *inode)
343{
344 return mutex_lock_interruptible(&OVL_I(inode)->lock);
345}
346
347static inline void ovl_inode_unlock(struct inode *inode)
348{
349 mutex_unlock(&OVL_I(inode)->lock);
350}
351
352
353
354int ovl_check_fb_len(struct ovl_fb *fb, int fb_len);
355
356static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len)
357{
358 if (fh_len < sizeof(struct ovl_fh))
359 return -EINVAL;
360
361 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET);
362}
363
364struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
365 bool connected);
366int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
367 struct dentry *upperdentry, struct ovl_path **stackp);
368int ovl_verify_set_fh(struct dentry *dentry, const char *name,
369 struct dentry *real, bool is_upper, bool set);
370struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
371int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
372int ovl_get_index_name(struct dentry *origin, struct qstr *name);
373struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
374struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
375 struct dentry *origin, bool verify);
376int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
377struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
378 unsigned int flags);
379bool ovl_lower_positive(struct dentry *dentry);
380
381static inline int ovl_verify_origin(struct dentry *upper,
382 struct dentry *origin, bool set)
383{
384 return ovl_verify_set_fh(upper, OVL_XATTR_ORIGIN, origin, false, set);
385}
386
387static inline int ovl_verify_upper(struct dentry *index,
388 struct dentry *upper, bool set)
389{
390 return ovl_verify_set_fh(index, OVL_XATTR_UPPER, upper, true, set);
391}
392
393
394extern const struct file_operations ovl_dir_operations;
395int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
396void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
397void ovl_cache_free(struct list_head *list);
398void ovl_dir_cache_free(struct inode *inode);
399int ovl_check_d_type_supported(struct path *realpath);
400int ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
401 struct dentry *dentry, int level);
402int ovl_indexdir_cleanup(struct ovl_fs *ofs);
403
404
405int ovl_set_nlink_upper(struct dentry *dentry);
406int ovl_set_nlink_lower(struct dentry *dentry);
407unsigned int ovl_get_nlink(struct dentry *lowerdentry,
408 struct dentry *upperdentry,
409 unsigned int fallback);
410int ovl_setattr(struct dentry *dentry, struct iattr *attr);
411int ovl_getattr(const struct path *path, struct kstat *stat,
412 u32 request_mask, unsigned int flags);
413int ovl_permission(struct inode *inode, int mask);
414int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
415 const void *value, size_t size, int flags);
416int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
417 void *value, size_t size);
418ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
419struct posix_acl *ovl_get_acl(struct inode *inode, int type);
420int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);
421bool ovl_is_private_xattr(const char *name);
422
423struct ovl_inode_params {
424 struct inode *newinode;
425 struct dentry *upperdentry;
426 struct ovl_path *lowerpath;
427 bool index;
428 unsigned int numlower;
429 char *redirect;
430 struct dentry *lowerdata;
431};
432void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,
433 unsigned long ino, int fsid);
434struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
435struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
436 bool is_upper);
437bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir);
438struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir);
439struct inode *ovl_get_inode(struct super_block *sb,
440 struct ovl_inode_params *oip);
441static inline void ovl_copyattr(struct inode *from, struct inode *to)
442{
443 to->i_uid = from->i_uid;
444 to->i_gid = from->i_gid;
445 to->i_mode = from->i_mode;
446 to->i_atime = from->i_atime;
447 to->i_mtime = from->i_mtime;
448 to->i_ctime = from->i_ctime;
449 i_size_write(to, i_size_read(from));
450}
451
452static inline void ovl_copyflags(struct inode *from, struct inode *to)
453{
454 unsigned int mask = S_SYNC | S_IMMUTABLE | S_APPEND | S_NOATIME;
455
456 inode_set_flags(to, from->i_flags & mask, mask);
457}
458
459
460extern const struct inode_operations ovl_dir_inode_operations;
461int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir,
462 struct dentry *dentry);
463struct ovl_cattr {
464 dev_t rdev;
465 umode_t mode;
466 const char *link;
467 struct dentry *hardlink;
468};
469
470#define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
471
472struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
473 struct ovl_cattr *attr);
474int ovl_cleanup(struct inode *dir, struct dentry *dentry);
475struct dentry *ovl_lookup_temp(struct dentry *workdir);
476struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
477
478
479extern const struct file_operations ovl_file_operations;
480int __init ovl_aio_request_cache_init(void);
481void ovl_aio_request_cache_destroy(void);
482
483
484int ovl_copy_up(struct dentry *dentry);
485int ovl_copy_up_with_data(struct dentry *dentry);
486int ovl_maybe_copy_up(struct dentry *dentry, int flags);
487int ovl_copy_xattr(struct dentry *old, struct dentry *new);
488int ovl_set_attr(struct dentry *upper, struct kstat *stat);
489struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper);
490int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
491 struct dentry *upper);
492
493
494extern const struct export_operations ovl_export_operations;
495